There is an alternate world out there in the multiverse. A world governed by Slasher movie tropes. An unspeakable powerful force came to that world a long time ago and, over time, influenced individuals it found suitable to become murderous monsters in human form.

They were categorized as:

1: Legendary/Empowered. Those who became so ingrained in the supernatural and have become powerful inhuman entities (like Freddy Krueger, Pinhead and so on)

2: The Masks/Enhanced. Those who, through the influence of the unholy force, became unstoppable killing machines with practically no trace of humanity in them (Jason Voorhees, Michael Myers, Leatherface and so on)

3: The Insane/Maniacs. Those who are human in body, with no enhancements or powers. They rely on their tighter grasp on real life and intellect since a lot of the time they are even weak physically. (Lector Hannibal, Chucky,Norman Bates and so on)

4: The Posers. There are those who are either unhealthily fascinated by the Slasher individuals, or convinced that the only way to survive in this horrible, killer-filled world is to become one. (Ghostface, Leslie Vernon, the killers from You're Next)